Dose-volume histogram parameters of high-dose-rate brachytherapy for Stage I-II cervical cancer (≤4cm) arising from a small-sized uterus treated with a point A dose-reduced plan

We investigated the rectal dose-sparing effect and tumor control of a point a dose-reduced plan in patients with stage i-ii cervical cancer (≤4 cm) arising from a small-sized uterus. between october 2008 and august 2011,19 patients with stage i-ii cervical cancer (≤4 cm) were treated with external beam radiotherapy (ebrt) for the pelvis and ct-guided brachytherapy. seven patients were treated with brachytherapy with standard loading of source-dwell positions and a fraction dose of 6 gy at point a (conventional brachy-plan). the other 12 patients with a small uterus close to the rectum or small intestine were treated with brachytherapy with a point a dose-reduction to match d2cc of the rectum and <6 gy as the dose constraint ('point a dose-reduced plan') instead of the 6-gy plan at point a ('tentative 6-gy plan'). the total doses from ebrt and brachytherapy were added up and normalized to a biological equivalent dose of 2 gy per fraction (eqd2). the median doses to the high-risk clinical target volume (hr-ctv) d90 in the conventional brachy-plan,tentative 6-gy plan and point a dose-reduced plan were 62 gyeqd2,80 gyeqd2 and 64 gyeqd2,respectively. the median doses of rectal d2cc in the corresponding three plans were 42 gyeqd2,62 gyeqd2 and 51 gyeqd2,respectively. with a median follow-up period of 35 months,three patients developed grade-1 late rectal complications and no patients developed local recurrence. our preliminary results suggested that ct-guided brachytherapy using an individualized point a dose-reduced plan might be useful for reducing late rectal complications while maintaining primary tumor control. © 2014 the author.